Heat exchanger



g- 1966 H. J. SCHROEDER HEAT EXCHANGER Filed April 2. 1962 III/ffirae All/vs Joan n crew ar 42% #7738175),

United States Patent 3,265,120 HEAT EXCHANGER Hans Joachim Schroeder, Munich, Germany, assignor to BMW Triebwerkbau Gesellschaft m.b.H., Munich- Allach, Germany Filed Apr. 2, 1962, Ser. No. 184,392 7 Claims priority, application Germany, Apr- 7, 1961, B 62,046 7 Claims. (Cl. 165-6) The present invention relates to a regenerative heat exchanger with a rotating, annularly-shaped heat exchanging mass, in which the heat-exchanging mass consists of individual, stacked, annularly-sh-aped laminae which are independent of one another and combined into a pack or stack and which consists, for instance, of thin laminae made from sheet metal, which are compressed in the separating and sealing plane between the heat exchanging media-for example, hot gas and cold air-by packing o-r sealing rollers serving simultaneously as drive for the he atexchanging mass.

In this known arrangement, spacer means, such as intermediate rings, tongue combs, etc. are arranged along the circular are between the individual laminae for maintaining the free flow cross section, i.e., in order to enable passage of the heat-absorbing and heat-transferring media between the laminae. .T he use of such spacer means is, however, very disadvantageous as .with the great number of laminae, also a great number of spacers is required and therewith considerable friction is caused so that it is very diflicult to rotate the lamellar pack.

As a result of the installation of the spacer means, the total weight of the regenerator is considerably increased on the one hand, and, on the other hand, the installation of such spacer means involves increased expenditures and therewith a considerable increase in cost.

The present invention aims at eliminating these drawbacks and proposes therefor that merely by the manner of clamping the heatcxchanging mass or the lamellar pack by means of pairs of sealing rollers, there is formed inherently a gap or interstice between individual laminae, starting from the separating-and sealing plane in which the laminae are pressed against each other in a gas-tight manner, which enables the passage of the heat-exchanging media.

The advantages of the present invention substantially reside in the fact that, by the elimination of the spacer elements between the individual laminae, the regenerator may be manufactured in a more simple manner and its total weight is considerably lighter compared to the known arrangements. Added thereto are the savings in material costs, in manufacturing costs for the spacer means as well as in the costs for the installation thereof. Furthermore, by reason of the elimination of friction between the laminae and the spacer elements, a considerably smaller power is required for the drive of the heat-exchanging mass as compared to the known arrangements.

The present invention further proposes that the annular laminae be supported both in the axial and in the radial direction by two or more pairs of sealing rollers, whereby these rollers are each provided in the axial direction with a conical contact surface against which the outermost laminae of the lamellar package will rest with the outer lateral surfaces thereof, while the end faces or surfaces of the laminae will rest against the cylindrical part of the seal- Patented August 9, 1966 ing rollers. In this manner, a single, double, or multiple bent surface is (formed by the particular manner of clamping or holding of the lamellar pack at the conical contact surfaces depending upon whether the contact surfaces of the pairs of sealing rollers are inclined with respect to each other or extend parallelly, whereby a gap will necessarily be formed between adjacent laminae, whose maximum width is preferably produced in the center of the circular are between the respective clamping places, i.e., in the center between the sealing and separating plane, and is determined by the thickness of the laminae and the angle on under which the laminae rest against the contact surfaces of the sealing rollers.

A self-cleaning action of the laminae is achieved by this automatically expanding and closing gap, which action, according to another feature of the present invention, is increased by the fact that, with the use of several pairs of rollers for driving and sealing the lamellar package or stack, a multiple bent surface is formed whereby, with the use of more than two pairs of sealing rollers, for example, the third pair of rollers will serve to guide the lamellar package. Cleaning of the heat exchanger mass is realized in an advantageous manner merely by self-cleaning action due to the multiple change in the bend of each lamina during one revolution and by the squeezing effect during passage through the separating barriers, i.e., at the sealing and separating plane.

Accordingly, it is an object of the present invention to provide a regenerative heat exchanger having rotating lamellae which automatically and necessarily provides interstices for the passage of the fluid media in the heat exchanger.

It is another object of the present invention to provide a heat exchanger of the type mentioned hereinabove which obviates the need for spacers between adjacent lamellae and therewith effectively permits considerable reduction in weight as well as significant decrease in manufacturing and assembly costs.

A further object of the present invention resides in the provision of a heat exchanger having rotary lamellae in which the friction in driving the lamellae is considerably reduced thereby greatly facilitating rotation of the stack of the lamellae.

Still another object of the present invention resides in the provision of a heat exchanger of the type mentioned hereina-bove in which the number of gaps'or interstices as well as the configuration thereof may be readily controlled by the mode of clamping the lamellae at the sealing places by means of the utilized sealing rollers.

A further object of the present invention resides in the provision of a heat exchanger having a stack of lamellae which offers a self-cleaning action.

These and other objects, features and advantages will become more obwious from the following description when taken in connection with the drawing which shows, for purposes of illustration only, several embodiments of a regenerative heat exchanger in accordance with the present invention, illustrated in the drawing only schematically and providing, for sake of clarity, only a simplified illustration of those parts such as the regenerator housing, airand gas-inlets and outlets, and omitting the drive means of the heat exchanger mass, which are unimportant for the principle of construction of the regenerator in accordance with the present invention, and wherein FIGURE 1 is a top plan view of a regenerative heat exchanger according to the present invention;

FIGURE 2 is a side view of the heat exchanger shown in FIGURE 1;

FIGURE 3 is a top plan view of a modified embodiment of a regenerative heat exchanger according to the present invention;

FIGURE 4 is a side view of still another embodiment of a regenerative heat exchanger in accordance with the present invention;

FIGURE 5 is a top plan view, on an enlarged scale, of two adjacent laminae according to FIGURE 3, and

FIGURE 6 is a top plan view also, on an enlarged scale, of two adjacent laminae according to FIGURES 1 and 2.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate corresponding parts reference numeral 1 designates therein two or several pairs of sealing rollers 1 which are rotatably supported with a housing 11 (FIG. 2) and which serve for guiding and centering as well as for driving the annularly shaped laminae 2 which are independent of each other and combined into a pack, and which are made from thin sheet metal. Each pair of sealing rollers 1 presses the laminae 2 against each other in a gas-tight manner and effectively form together with these gas-tight, pressed-together laminae 2, a separating and sealing plane 3 by means of which the regenerator or regenerator housing 11 (FIG. 2) is subdivided into two spaces or chambers, namely the gas chamber 4 into which are introduced via an inlet (not shown), for instance, the hot gases, and the cool air chamber 5 into which flows the cold air through inlet 5' and in which the cold air is heated therein by heat exchange. The gases and air in the respective chambers are then discharged through suitable outlets, such as outlet 4 for the cooled gas in chamber 4. The inlet for chamber 4 and the outlet for chamber 5, not shown in the drawings, may be arranged on opposite sides of the apparatus in the well known and conventional manner.

Each pair of sealing rollers 1 is composed to two sealing rolls, each such sealing roll having a conical abutment surface 6 in the axial direction and at opposite ends thereof, for the laminae 2. A cylindrical portion 7 adjoins this abutment surface 6. The laminae 2 are held both in the axial and in the radial direction thereof by two or more pairs of sealing rollers 1 and/or 1' corresponding to the illustrated embodiments, whereby in each case the outermost laminae of the lamellar pack abut in the axial direction against the conical contact surfaces 6 With the outer lateral surfaces thereof whereas, in the radial direction, the laminae 2 abut with both the inner and the outer end surfaces 8 and 8' against the cylindrical part 7 of the sealing rolls.

Operation The functioning and operation of the regenerator according to the present invention is as follows:

The laminae 2 serving as heat exchange mass are held together by the pairs of sealing rollers 1, as already described hereinabove, are driven by the latter and thus rotate within the regenerator housing 11. A gap or interstice 9, enabling the passage of the heat-exchanging media, is necessarily formed in this manner between the individual laminae 2 exclusively by the particular manner of clamping the laminae 2 by means of the pairs of sealing rollers 1, starting from the separating and sealing plane 3 in which the laminae 2 are pressed together in a gas-tight manner. The maximum width of the gap 9 is preferably formed in the center of the circular are between the respective clamping points, i.e., be-- ing to the present invention, a gap 9 which increases up to a maximum value and which renders possible the passage of the heat-exhanging media and therewith the absorption and the giving off of heat, is thus formed between the two heat-exchanging media after passage of the lamellar pack through the sealing and separating plane 3 in which the chambers 4 and 5, under different pressure, have to be sealed to avoid exhaust and leakage losses, and in which the laminae are, therefore, pressed together in a gas-tight manner. In order to achieve a faultless sealing, i.e., a satisfactory abutment of the laminae 2 against the cylindrical part 7 of the sealing rollers 1, the edges of the end surfaces of the laminae 2 abutting against that part may be bevelled.

FIGURES 1 and 2 show a regenerator with two pairs of sealing rollers 1. The conical abutment surfaces 6 of the sealing rollers 1 are inclined with respect to each other and form planes 10 in such a manner that the lameller package as seen in plan view, necessarily forms a single-curved surface.

FIGURE 3 illustrates an embodiment of the present invention which has substantially the same construction as the embodiment shown in FIGURES 1 and 2, but wherein the conical abutment surfaces 6 and the planes 10' of the sealing rollers 1 extend parallelly to each other so that, by reason of the particular manner of clamping the lamellar package will form-as viewed in plan view, a double-curved surface of substantially S-shaped. In this embodiment, a gap 9 is again necessarily formed between the individual laminae 2.

When using accordance with the present invention two pairs of sealing rollers 1 as guide, sealing-and drive-element, then the lamellar package may be stretched laterally to a small extent at the separatingand sealing plane 3 (FIG 2) in order to achieve a predetermined pre-stress of the lamellar package and therewith a certain centering effect if the laminae 2.

FIGURE 4 illustrates an embodiment of the present invention wherein the pairs of sealing rollers 1 are so arranged that the gas chamber 4 has, for instance, twice the size of the air chamber 5. In order to prevent fluttering and chattering of the laminae 2 along the large circular are between the clamping points, an additional pair of rollers 1' is used within the gas chamber 4 between the two pairs of sealing rollers 1, whereby the roller pair 1' merely serves for guiding the lamellar package. In this embodiment, in which more than two pairs of rollers are utilized, a multiple-curved surface will be formed whereby, however, a gap 9 will always be formed again, which permits passage of the heat-emitting and the heat-absorbing working media, by reason of the conical abutment surface 6 of the laminae 2 at the pairs of rollers. The curvature of the lamellar package may be made as desired, depending on how many pairs of rollers are used and on whether the abutment surfaces 6 are parallel or inclined with respect to each other.

In order to hold the lamellar package together in a form-locking manner, there may be imparted to the individual laminae a radially-directed undulation or wave-like configuration along their ring-shaped surface, extending over the entire circumference and not shown in the drawing.

While I have shown and described several embodiment in accordance with the present invention, it is understood that the same is not limited thereto, but is susceptible of many changes and modifications within the spirit and scope of a person skilled in the-art, and I therefore do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

I claim:

1. In a regenerative heat exchanger, a heat exchanging mass comprising heat exchanger means including a plurality of individual stacked, annularly-shaped relatively thin rotary lamellae independent of one another, and clamping means compressing said lamellae in a gas tight manner in at least two spaced zones forming a sealing plane separating the heat exchanging media and serving simultaneously as drive means for said lamellae, said clamping means including pairs of sealing roller means forcibly producting a gap between individual lamellae, said gap increasing with the distance from said sealing plane, which gap enables the passage of the heat exchanging media therethrough, said pairs of sealing roller means supporting said laminae in both the axial and radial direction, and each sealing roller means having, on the one hand, substantially conical abutment surface means oppositely disposed in pairs and forming an acute angle in the axial direction with the axis of said roller means against which abut the outermost laminae of the stack of laminae with the facing surfaces thereof, and, on the other hand, substantially cylindrical portions against which abut the end faces of said lamellae.

2. In a regenerative heat exchanger, a heat exchanging mass comprising heat exchanger means including a plurality of individual stacked, annularly-shaped relatively thin rotary lamellae independent of one another, and clamping means compressing said lamellae in a gas-tight mannerin at least two spaced zones forming a sealing plane separating the heat exchanging media and serving simultaneously as drive means for said lamellae, said clamping means including pairs of sealing roller means forcibly producing a gap between individual lamellae, said gap increasing with distance from said sealing plane, which gap enables the passage of the heat exchanging media therethrough, said pairs of sealing roller means supporting said laminae in both the axial and radial direction, and each sealing roller means having, on the one hand, substantially conical abutment surface means oppositely disposed in pairs in the axial direction against which abut the outermost laminae of the stack of laminae with the facing surfaces thereof, and, on the other hand, substantially cylindrical portions against which abut the end faces of said lamellae, the maximum width of the gap between adjacent lamellae being determined by the thickness of the lamellae and by the angle at which said lamellae abut against said abutment surface means.

3. In a regenerative heat exchanger, a heat exchanging mass comprising heat exchanger means including a pinrality of individual stacked, annularly-shaped relatively thin rotary lamellae independent of one another, and clamping means compressing said lamellae in a gas-tight manner in at least two spaced zones forming a sealing plane separating the heat exchanging media and serving simultaneously as drive means for said lamellae, said clamping means including pairs of sealing roller means forcibly producing a gap between individual lamellae, said gap increasing with distance'from said sealing plane, which gap enables the passage of the heat exchanging media therethrough, said pairs of sealing roller means supporting said laminae in both the axial and radial direc tion, and each sealing roller means having, on the one hand, substantially conical abutment surface means oppositely disposed in pairs in the axial direction against which abut the outermost laminae of the stack of laminae with the facing surfaces thereof, and, on the other hand, substantially cylindrical portions against which abut the end faces of said lamellae, the maximum width of the gap between adjacent lamellae being determined by the thickness of the lamellae and by the angle at which said lamellae abut against said abutment surface means, and the maximum width of the gap occurring solely through distortion of said lamellae by said roller means substantially in the center of the arc between respective clamping places formed by the sealing roller means.

4. In a regenerative heat exchanger, a heat exchanging mass comprising heat exchanger means including a plurality of individual stacked, annularly-shaped relatively thin rotary lamellae independent of one another, and

clamping means compressing said lamellae in a gas-tight manner in at least two spaced zones forming a sealing plane separating the heat exchanging media and serving simultaneously as drive means for said lamellae, said clamping means including pairs of sealing roller means forcibly producing a gap between individual lamellae, said gap increasing with distance from said sealing plane, which gap enables the passage of the heat exchanging media therethrough, said pairs of sealing roller means supporting said laminae in both the axial and radial direction, and each sealing roller means having, on the one hand, substantially conical abutment surface means oppositely disposed in pairs in the axial direction against which abut the outermost laminae of the stack of laminae with the facing surfaces thereof, and, on the other hand, substantially cylindrical potrions against which abut the end faces of said lamellae, and the maximum width of the gap occurring solely through distortion of said lamellae by said roller means substantially in the center of the are between respective clamping places formed by the sealing roller means.

5. In a regenerative heat exchanger, a heat exchanging mass comprising heat exchanger means including a plurality of individual stacked, annularly-shaped relatively thin rotary lamellae independent of one another, and

clamping means compressing said lamellae in a gas-tight manner in at least two spaced zones forming a sealing plane separating the heat exchanging media and serving simultaneously as drive means for said lamellae, said clamping means including pairs of sealing roller means forcibly producing a gap between individual lamellae, said gap increasing with distance from said sealing plane, which gap enables the passage of the heat exchanging media, said pairs of sealing roller means supporting said laminae in both the axial and radial direction, and each sealing roller means having, on the one hand, substantially conical abutment surface means oppositely disposed in pairs in the axial direction against which abut the outermost laminae of the stack of laminae with the facing surfaces thereof, and, on the other hand, substantially cylindrical portions against which abut the end faces of said lamellae, said abutment surface means being inclined toward each other at an acute angle to the axis of said roller means to thereby impart to the stack of lamellae a single curvature.

6. In a regenerative heat exchanger, a heat exchanging mass comprising heat exchanger means including a plurality of individual stacked, annularly-shaped relatively thin rotary lamellae independent of one another, and clamping means compressing said lamellae in a gas-tight manner in at least two spaced zones forming a sealing plane separating the heat exchanging media and serving simultaneously as drive means for said lamellae, said clamping means including pairs of sealing roller means forcibly producing a gap between individual lamellae, said gap increasing with distance from said sealing plane, which gap enables the passage of the heat exchanging media therethrou-gh, said pairs of sealing roller means supporting said laminae in both the axial and radial direction, and each sealing roller means having, on the one hand, substantially conical abutment surface means 0ppositely disposed in pairs in the axial direction against which abut the outermost laminae of the stack of laminae wtih the facing surfaces thereof, and, on the other hand, substantially cylindrical portions against which abut the end faces of said lamellae, said abutment surface means being substantially parallel to one another and at an acute angle to the axis of said roller means to thereby impart to the stack of lamellae a double curvature.

7. In a regenerative heat exchanger, a heat exchanging mass comprising heat exchanger means including a plurality of individual stacked, annularly shaped relatively thin rotary lamellae independent'of one another, and clamping means compressing said lamellae in a gas-tight manner in at least two spaced zones forming a sealing plane separating the heat-exchanging media and serving simultaneously as drive means for said lamellae, said clamping means including pairs of sealing roller means forcibly producing a gap between individual lamellae, said gap increasing with distance from said sealing plane, which gap enables the passage of the heat-exchanging media, said pairs of sealing roller means supporting said lamellae in both the axial and radial direction, and each of said sealing roller means having a frusto-conical end portion tapering at an acute angle in the axial direction of said roller means towards said lamellae, against which abut the outermost lamellae of the stack of larnellae with the other axial surfaces thereof, and a substantially cy- -lindrical portion contiguous to the narrower end of said frusto-conical end portion, the radial end faces of said lamellae abutting against said cylindrical portions.

References Cited by the Examiner UNITED STATES PATENTS 1,035,322 8/1932 Cuddihy 198-192 2,915,297 12/1959 Lange 165-9 2,932,492 4/1960 Lange 165--9 FOREIGN PATENTS 723,717 8/1942 Germany.

ROBERT A. OLEARY, Primary Examiner.

PERCY L. PATRICK, CHARLES SUKALO, Examiners.

T. W. STREULE, Assistant Examiner. 

1. IN A REGENERATIVE HEAT EXCHANGER, A HEAT EXCHANGING MASS COMPRISING HEAT EXCHANGER MEANS INCLUDING A PLURALITY OF INDIVIDUAL STACKED, ANNULARLY-SHAPED RELATIVELY THIN ROTARY LAMELLAE INDEPENDENT OF ONE ANOTHER, AND CLAMPING MEANS COMPRESSING SAID LAMELLAE IN A GAS TIGHT MANNER IN AT LEAST TWO SPACED ZONES FORMING A SEALING PLANE SEPARATING THE HEAT EXCHANGING MEDIA AND SERVING SIMULTANEOUSLY AS DRIVE MEANS FOR SAID LAMELLAE, SAID CLAMPING MEANS INCLUDING PAIRS OF SEALING ROLLER MEANS FORCIBLY PRODUCING A GAP BETWEEN INDIVIDUAL LAMELLAE, SAID GAP INCREASING WITH THE DISTANCE FROM SAID SEALING PLANE, WHICH GAP ENABLES THE PASSAGE OF THE HEAT EXCHANGING MEDIA THERETHROUGH, SAID PAIRS OF SEALING ROLLER MEANS SUPPORTING SAID LAMINAE IN BOTH THE AXIAL AND RADIAL DIRECTION, AND EACH SEALING ROLLER MEANS HAVING, ON THE ONE HAND, SUBSTANTIALLY CONICAL ABUTMENT SURFACE MEANS OPPOSITELY DISPOSED IN PAIRS AND FORMING AN ACUTE ANGLE IN THE AXIAL DIRECTION WITH THE AXIS OF SAID ROLLER MEANS AGAINST WHICH ABUT THE OUTERMOST LAMINAE OF THE STACK OF LAMINAE WITH THE FACING SURFACES THEREOF, AND ON THE OTHER HAND, SUBSTANTIALLY CYLINDRICAL PORTIONS AGAINST WHICH ABUT THE END FACES OF SAID LAMELLAE. 